The present invention relates to projectors and more particularly to a projector having improved characteristics such as with image source from objects in addition to paper, color film, and transparent slide.
A conventional projector is shown in FIG. 1 comprising a light source 10, a reflection mirror 11 for reflecting light emitted from light source 10, a focusing lens 12 for bringing together light from reflection mirror 11 to pass through an image source (e.g., transparent slide) 13, and a projecting lens 14 for reflecting light from transparent slide 13 and throwing the image of the transparent slide 13 on a screen 15. Such transparent slide 13 is usually made of plastic material. Also, transparent slides 13 are applicable to liquid crystal based projection plate.
However, the conventional projector, irrespective of the slide being color or black-white, suffered from a number of disadvantages as detailed below.
1. It is time consuming and expensive for producing transparent slides because data is required to copied on slide in advance.
2. The transparency of color slide is poor. This adversely affects the color of image.
3. The proposal of waste transparent slides is a burden to the environment.
4. As to liquid crystal based projection plate, it is expensive and poor in color and contrast.
5. There is a diffusion loss when light transmitted from light source to projecting lens.
6. There is a superposition effect on the projected image on screen due to the projection of diffused light thereon. This causes a poor image contrast.
7. Viewer may suffer eye fatigue after viewing the image on screen for a relatively long time.
8. It is impossible to project an object.
Thus, it is desirable to provide an improved projector with image source from objects in order to overcome the above drawbacks of prior art.
It is an object of the present invention to provide a projector capable of throwing image on a screen from objects, the project comprising a base including a mirror on either side, two second small mirrors on both top and bottom sides of each mirror, small mirror being at an oblique angle with respect to mirror, a rear slanted plate with lower portion hinged to the bottom plate of base such that the rear slanted plate may pivot about the hinge, a third mirror on the inner surface of the rear slanted plate, a lens in the front board, an arcuate heat resistant plate above the lens, a drawer in the receiving space of the base for putting object(s) therein, and a cover hinged on the front board of base; an angle adjustment means on the outside of the rear slanted plate for adjusting the angle of the rear slanted plate with respect to base including an elongate shaft with both ends passed through the sides of base, a turning member pivotably put on the shaft having an arcuate recess, and a short shaft passed through the arcuate recess having both ends attached to the outer surface of the rear slanted plate; a light source on the upper portion of base for emitting light which is concentrated on the side mirrors of the base; a housing shaped to conform with base so as to cover the projector; and a cooling means on the rear board of housing wherein object is put on the drawer which is inserted in the receiving space of base from opening, the image of object is reflected on third mirror, the image is further reflected on lens in the front board of base, by turning the focusing knob associated with the lens for obtaining a clear image on the screen; and pivot the turning member toward short shaft in order to bias the rear slanted plate for adjusting the angle of the rear slanted plate so as to obtain a better angle of the lens for enhancing focus.
It is another object of the present invention to provide a projector further comprising a ventilation opening on either side of the base, two second ventilation openings on the front side of the base, and three sets of ventilation slots on the housing corresponding to the ventilation openings provided on two side boards and top board of housing respectively. With this, it is made possible to effectively dissipate heat generated in use so as to maintain the normal operation of projector.
The above and other objects, features and advantages of the present invention will become apparent from the following detailed description taken with the accompanying drawings.